Hydrogen Air Reaction Mechanism And Basic Combustion Characteristics

With the scarcity of oil resources,the deterioration of the global environment,emission limits on emissions regulations become more and more stringent.The use of clean energy and renewable energy has become the first choice.Wherein,the hydrogen combustion is clean and renewable,it is a promising alternative fuel of internal combustion engine.Previous researchers have made a more systematic development and research of hydrogen energy,however,the study of hydrogen combustion characteristics of the air base,hydrogen/air chemical reaction mechanism has yet to be intensified.Firstly,this paper based on combustion test system platform,the partial pressure of the mixed gas composition matching method,spark ignition directly,were studied laminar combustion characteristics of hydrogen/air mixture.Test results of different fuel-air equivalence ratio and initial temperature of the influence on the unstretched laminar burning velocity of the flame,temperature in burned zone,Markstein length,the results showed that:within the study area,laminar burning velocity and the temperature in burned zone with the equivalence ratio increases then decreases;with increasing initial temperature increases,the maximum temperature in burned zone are already present in the fuel-air equivalence ratio of1.0.Then,the application of chemical reaction dynamics software CHEMKIN,using sensitivity analysis,generating rate and reaction path analysis,discussed in detail the course of chemical reactions under different equivalence ratio of hydrogen peroxide,it is concluded that the different mixture concentration has influence to the reaction process,proposed for describing hydrogen air premixed laminar burning velocity consists of 14 elementary,26 steps to simplify the mechanism of the reaction,and the simplified mechanism is analyzed.Finally,in order to further study the combustion characteristics of hydrogen fuel internalcombustion engine,based on the combustion model of a simplified chemical reaction mechanism,hydrogen combustion process were simulated,respectively discussed compression ratio,speed,EGR and intake air temperature on the influence of the combustion process in cylinder.The study found that the compression ratio,speed and intake air temperature and many other parameters,will have an impact on running the hydrogen fueled internal combustion engine;hot EGR technology can effectively reduce the in-cylinder temperature and cylinder pressure,and thus reducing NO emissions,but larger EGR rate will lead to a rapid decline in the efficiency of the hydrogen internal combustion engine.